Flexible swab



May 3, 1927.

FLEXIBLE SWAB E. w. FORROW Filed May 19. 1925 Patented May 3, 1927.

Erwin w. FOBBOW, or ANAHEIM, .camronnm.

rmxmra swan;

Applicatioziflled Kay 19, 1925. Serial No. si,so9.

This invention relates to flexible swabs'and is more particularly directed to a swab for use in swabbing oil well tubes and the like, and which swab is composed of a plurality of sections so that the same is flexible and in which swab a plurality of packing cups are provided for maintaining afluid tight connection between the swab and the oil well tubing when the same is used for the purpose of swabbing out the said tubing. As is commonly known, very few, if any, oil well bor'es are straight. The casing-positioned within these bores assumes approximately the shape of the bore and the tubing or fluid string suspended within the well in the easing is likewise curved at infrequent intervals practically throughout its entire length.

In swabbing wells for the purpose of removing the sands which operate to clog the pump, or for the purpose of causing the oil well to flow, it is extremely difficult to lower the swabs as commonly used (which areof rigid construction) to the bottom of the well so that this lowering is accomplished generally by literally dropping the swab from the top of the well and allowing the same to gain momentum sufficient to carry it past the bends or curves in the pipe. A cable is connected to the end of the swab and is lowered upon a drum within the oil well rig. In

order to allow the free fall of the swab into the well, thedrum must be free 'to rotate and the play of the cable often exceeds the travel of the swab into the well and flaps about upon the rig floor, often forming loops which are very dangerous to the op erators attempting to swab the well, and to clog machinery and parts situated within the rig, as well as to the rig itself.

In order to enable the swabto be driven out from the well past these curved portions of the pipe, the cable. is wound upon the drum at the maximum speed of the engine connected therewith. The swab is also pulled from the well at a high rate of speed so as to produce a suction throughout the entire fluid string. However, when the swab encounters one of the curved portions of the pipe and is travelling at a high rate of speed, a severe strain is put upon the cable which often results in the same breaking and leaving the swab within'the well. It is,

I therefore, an object of this invention to provide a swab made up of sections so that the same is flexible throughout its length and so that the same may be easily lowered into the well and the swab will follow thecontour or curve of the pipewhen so lowered.

It is an object of this invention to provide a swab having a plurality of paekin Cups 00 expandible when the swab is raised in the well to provide a fluid tight connection between the swab parallel to the fluid string.

An object of this invention is to provide a swab having a plurality of separatepack mg cups receiving chambers into which the fluid in the well, such as oil, is adapted to flow during the lowering of the swab into the well so that the fluid will act to force the packing cups outward into engagement with" the walls of the fluid string when the swab is raised from the well.

An object ofthis-invention is to provide a swab having a plurality of packing cups which present a relatively small wearing 76 Surface maintaining a fluid tight connection with the fluid string.

Other ob 'ects and advantages of this invention will be apparent from the followin detailed description of a preferred embodi- 80 ment thereof as illustrated in the accompanying drawings, in which- Fig. 1 is a side elevation of a swab embodied in this invention, illustrating the same as in position within the fluid string 86 of a well shown in section.

Fig. 2is an enlarged fragmental central sectional side elevation of a swab embodying this invention.

Fig. 3 is anenlarged central sectional side I elevation of the swab, broken away from Fig. 2.

Fig. 4 is a sectional end elevation, taken substantially on the line 4-4, Fig. 2.

Fig. 5 isafront perspective view of a packing cup embodied in this invention, illustrating the same partly ,broken away.

In the preferred embodiment of this invention shown in the drawings, 1 illustrates a cable clamp screw threaded to the upper section A of the swab, which swab is of slightly smaller external diameter than the fluid string 3 into which the same is to be inserted. The swab 2 is composed of a lurality of sections of any desired'num r, 1 such as the sections, A, B, .C.- D, and E. The sections A and O are held together by means of pins l which are centrally bored as illustrated at 5 to provide a continuous conduit through the center of the swab 2 which extends upward through the section A and communicates with the outwardly flanged ports 6 at the upper end of the swab and communicates with the interior of the valved housing 7 at the lower end of the swab in which valve housing 7 'a check valve is maintained of any suitable construction, such as that illustrated at -8. The section A comprises the tool joint 9 which is screw threaded to the cable clamp 1 as heretofore set forth at its upper end and is provided with. a chamber 10 at its lower end, which chamber 10 has an outwardly curved wall 11 so as to provide a chamber of increasing diameter from its upper end to its lower end. The chamber 10 is provided with a plurality of slots 11 through which the fluid within the fluid string 3 is admitted into the chamber 10 when the swab is being lowered into the well. The pin 4 connecting the section A to the section B passes through the bore 12 formed in the section B and is threaded to the section A as illustrated at 13. The section B provides at its upper cnd'a frusto-conical chamber 14 into which the lower portion of the packing cup 15 fits. The packing cup 15 has at its lower end a cylindrical bore 16 which closely fits the pin 4.

From the cylindrical bore 16 the cup 15 is internally bored so as to provide a chamber 17 of constantly increasing diameter from the bore 16 to its upper edge. The cup 15 is curved inwardly as illustrated at 18 above the position of normally fitting into the section B so as to provide a curved surface adapted to approximate the curve of the wall 11 of the chamber 10. The head 19 of the pin 4 engages the inwardly extending circumferential shoulder 20 upon the upper edge 21 of which the bottom of the packing cup 5 rests. The section B is secured to the section C by any suitable means, such as ill illustrated at 22. A chamber 23 is formed in the upper end of the section G to accommodate the heads 19 of the pins 4. The construction of the section C. otherwise than for its connection with the section B, is entirely similar to the construction of the section A. The construction of the section B is entirely similar to the COIlStlllCtlOIibll the section B. The construction of the lower section E is at its upper portion 24 entirely similar to the construction of the section B or I), but its lower section is cut away to provide a. shoulder 25 against which the nut 26 is forced when the same is screw threaded to the lower pin 4. A lock nutv 27 is screw threaded on the pin 4 in position to engage the nut 26 and hold the same from rotation.

The operation of this swab is that the same is lowered into the well and the fluid within the fluid string 2 passes upward through the ports 11 formed in the chambers 10. of the respective sections of the swab and fills the chamber 10 and the chamber 17 formed in the packing cups 15 so that when the swab is lowered to the lowest position within the well, the chambers 10 and 17 are 7 filled with fluid and there is a considerable column of fluid in the fluid string 3 above the swab 2. i The swab is then quickly raised and a pressure is exerted from above the swab upon the respective section tending to brace the same longitudinally, the edges ol the packing cup 15 extending between the respective sections of the swab being forced outwardly into engagement with the wall of the fluid string 2 providing a fluid tight.

seal.

The fluid within the chambers 10 and 1'? is compressed and exerts a pressure outwardly upon the walls of the cups 153 from within the chamber 17 so as to maintain the outer edge of the cups 15 at all times in fluid tight relation with the walls of the fluid string.

As only av small wearing sur't'ace is presented to the walls of the fluid string on wear of the cups 15. the fluid pressure within the chambers 10 and 17 continues to exert its influence on the nut 13 to continually force the same outward to maintain this fluid tight connection. By this manner of connection also the flexible swab is provided constructed of sections, and so united that the same is flexible between the connections formed wherein the cups 15 are interposed.

Having fully described a preferred embodiment of this invention. it is to be understood that it is not intended that the same should be limited to theexaet construction herein set forth, which may. obviously, be varied in detail without departing from the spirit of the appended claims.

I claim:

1. in a swab of the class described, the combination of a plurality of sections. means for connecting the sections in flexible relation and cup shaped packing members mounted on the connecting means between said sections and a fluid passage formed through the said sections and through the said connecting means.

2. in a swab of the class described, the combination of a plurality of sections means for connecting the sections in flexible relation, a fluid passage. through the sections, and flexible expandible packing members mounted upon the connecting means between the said sections. I

3. In a swab of the class described, the. combination of a plurality of sections. each section being provided with a chamber at its lower end and a packing receiving chamber in its upper end. flexible packing mounted in the said chamber in position to be en- 5. In a swab of the class described, the

combination of a plurality of sections, one of said sections providing a tool ioint for connecting the swab to a flexible cab e, means for connecting the sections in flexible rela-' tion, a fluid passage formed through the said connecting means, and means secured to the lower of said sections for restricting the fluid passage when the swab is raised.

6. In a swab of the class described, the combination of a plurality of sections, packing cups mounted between the sections,

'means for admitting fluid into the interior of the packing cups when the swab is lowered, and means for connecting the sections in flexible relation.

7. In a swab of the class described, the combination of a plurality of sections, packing cups mounted between the sections in chambers formed in the ends of the sections, means for admitting fluid into the interior of the packing cups when the swab is lowcred, and means for connecting the sections in flexible relation. 7

8. In a swab of the class described, the combination offaplurality of sections, packing cups mounted between the sections and chambers formed in the. ends of the sections in a manner to provide a relatively small cirtionsand said connecting means.

the sections in flexible. relation, afluid 'passage formed throu h the sections, and a cumferentiall extending packing shoulder, means for adi nitting fluid into the interior of the packing cup so as to force the packing cup outward to maintain the relatively small circumferential packing shoulder, means for connecting the sections in flexible relation, and a fluid passage formed through the sections and through the'said connecting means.

.9. In a swab, the combination of a plu rality of sections, chambers formed in'the ends of said sections, means connecting the said sections in flexible relation, a packing cup mounted in one chamber of each section and extending into'the chamber formed in the next adjacent section, ports formed in the end of each section which provides the chamber into which the-said cup pro'ects for, admitting fluid into the interior 0 the. said cups, a fluid passage formed through the said sections and connecting means and a check valve mountedin the said passage.

10. In a swab, the combination of a plurality of sections, means connecting the sections in flexible relation, packing cups mounted between the said sections for holding the said sections in spaced relation and a fluid passage formed through" he sai sec- 11. In a swab, the combination of a plurality of sections, packing cups mountedbe tween the sections, means for admitting fluid into the interior of the packing cups when the swab is lowered, means for connecting check valve mount in the-said passage.

Signed atAnaheim, California, this 26th day of February, 1925.

,Enwm w. ronnow. 

